Roller bearing rings

ABSTRACT

Annular mechanical elements such as bearing rings for roller bearings are manufactured by forming an annular steel blank of predetermined dimensions by a machining operation and subjecting the blank to a cold extrusions operation to provide an annular element of desired shape. The blank may be formed by the cold extrusion process into a multiplex structure which can be separated by a punching operation into two or more annular elements each of desired shape. The machining operation may be performed on the end of a seamless steel tube or a hot roller steel bar and the desired annular blank is then separated by a parting operation.

United States Patent [1 1 Knapp June 12, 1973 ROLLER BEARING RINGS [75]Inventor: Edward Ronald Knapp, Duston,

England I [73] Assignee: The Timken Company, Canton, Ohio 22 Filed: June14, 1971 [21] Appl. No.: 152,703

[30] Foreign Application Priority Data June 18, 1970 Great Britain29,747/70 [56] References Cited UNITED STATES PATENTS 12/1919 Timken1l/l959 Benson 4/1968 Cardillo 29/l48.4 R 2/1970 Constant 29/l48.4 R

[5 7] ABSTRACT Annular mechanical elements such as bearing rings forroller bearings are manufactured by forming an annular steel blank ofpredetermined dimensions by a machining operation and subjectingtheblank to a cold extrusions operation to provide an annular element ofdesired shape. The blank may be formed by the cold extrusion processinto a multiplex structure which can be separated by a punchingoperation into two or more annular elements each of desired shape. Themachining operation may be performed on the end of a seamless steel tubeor a hot roller steel bar and the desired annular blank is thenseparated by a parting operation.

8 Claims, 4 Drawing Figures 1 ROLLER BEARING RINGS The invention relatesto the manufacture of annular steel mechanical elements such as rollingbearing rings, for instance a cup and cone for a tapered roller bearing.

It is common practice to produce such parts by separating out theportions of a duplex form which has been extruded from an annular blank.The annular blank is produced from steel bar stock by the followingseries of operations.

The bar stock is ground to an even diameter and roundness.

A solid blank is cropped from the bar, the volume or weight of the blankbeing carefully controlled Degreasing Barrelling to remove sharp edgesPickling, phosphating and soaping Truing the end of the blank 4 Theblank is then pressed to shorten it and increase diameter Alkali washingAnnealing Phosphating and soaping lndenting and piercing the blank toproduce an annular form Alkali washing Annealing Phosphating andsoaping.

The annular blank thus produced can then be extruded into a duplex formwhich is subsequently punched to produce the separate bearing rings.

It will be seen that a total of operations are required to produce theannular blank. These operations are time consuming require specialmachinery and factory space, and are expensive in materials.Consequently they tend to dissipate the economic advantages looked forin the way of material savings by such use of simple bar stock and thechipless preparation of work pieces.

It is among the objects of the invention to provide a method ofmanufacturing annular mechanical elements in a simpler and fastermanner.

The invention therefore provides a method of manufacturing annularmechanical elements of steel which comprises forming an annular steelblank of predetermined dimensions by machining and subjecting the blankto a cold extrusion operation to form an annular element of desiredshape.

Preferably the steel blank is formed by the cold extrusion operationinto a multiplex structure which is then separated into portions, eachcomprising an annular element of desired shape, by a punching operation.

' The portions may be part of a duplex structure and when separated mayconstitute the cup and cone of a tapered roller bearing.

The annular metal blank is preferably machined to its desired internaland external dimensions whilst forming an end portion of a seamlesssteel tube or (for the smaller bearing sizes) a round hot rolled steelbar. The blank is then parted from the tube or bar stock and subjectedto the conventional preparatory procedures of degreasing, barrelling,phosphating and soaping before subjection to the extrusion and punchingsteps.

The invention also provides annular mechanical elements whenmanufactured by the method of the invention.

The invention will now be described with reference to the accompanyingdrawings in which: I

FIG. 1 is an axial section through an end portion of round hot rolledseamless steel tube stock formed annular element thereon,

FIG. 2 is an axial section through an end portion of round hot rolledsteel bar stock also showing an annular element part formed thereon,

FIG. 3 is an axial section through a duplex form of the kind extrudedfrom the annular element shown in FIGS. 1 and 2, and

FIG. 4 is an axial section through the duplex form of FIG. 3 whenseparated by punching its component parts.

Referring to the drawings, in the preparation of the annular blank forextrusion, the tube stock 1 or bar stock 2 is mounted in a lathe and theinner and outer diameters 3 and 4 of the terminal section 5 are machineddown to the requisite dimensions whilst a parting off tool is introducedat the outside diameter to separate off the blank at 6.

The annular blank 5 is then subjected in turn to degreasing, barrelling,phosphating and soaping opera tions and finally extruded in a press toform the duplex structure 7 of FIG. 3. The duplex structure is thenseparated into two parts 7a and 7b by a punching operation in a press.In the embodiment shown, the portion 7b can then be positioned withinthe portion 7a to form the cone of a roller bearing whilst the portion7a forms the cup.

Although the method as described is concerned with the manufacture ofonly two annular elements during each sequence of operations, clearlyone or several annular elements could readily be produced with theappropriate extrusion tooling and with appropriately dimensioned annularblanks.

It will be seen that the method of the invention substantially reducesthe number of operations required in order to produce the finishedbearing rings from the starting stock. This is due to the fact that theearlier methods have been principally concerned with chipless forming ofthe annular blank so as to avoid wastage of the relatively expensivealloy steel which it is necessary to use, particularly for rollerbearing rings. However the economic savings to be expected from theearlier practice is more than outweighed by the extensive preparatoryoperations necessary to form the annular blank by the earlier method.The preference for tube or bar stock is determined by the size of thebearing rings to be produced. With extremely small bearings, it is moreeconomical to use steel bar but as the size increases, the economicaladvantages of the use of steel tubing outweigh those of bar.

The external and internal machining of the annular blank proposed aspart of the process of the invention is particularly advantageous.,Thisis due to the fact that metallurgical defects are most likely to befound near the surfaces of hot rolled tube or bar and the external andinternal machining ensures that the defective metal portions are removedprior to the extrusion operation.

I claim:

1. A method of manufacturing a cup and cone for a tapered roller bearingfrom elongated stock; said method comprising: sizing the end of theelongated stock both internally and externally to prescribed diametersby machining; parting the sized end portion of the elongated stock fromthe remainder of stock to form an with a partly I annular blank;degreasing, barrelling, phosphating, and soaping the annular blank;thereafter extruding the ann'ular blank into a duplex structure havingtwo axially offset segments of different diameters; and separating theaxially offset segments in a punching operation, whereby the segment ofgreater diameter becomes the cup and the segment of lesser diameterbecomes the cone. V

2. A method of manufacturing bearing races from elongated steel stock,said method comprising: machining the stock both internally andexternally to impart prescribed external and internal diameters to theend of the stock and to remove metallurgical defects from the stock;parting at least a portion of the machined portion to form an annularblank, cold extruding the machined annular blank into a multiplexstructure having axially offset segments of annular shape and differentdiameters; and separating the segments of the multiplex structure in apunching operation, whereby the separated segments become bearing races.

3. A method of manufacturing bearing races from elongated steel stock,said method comprising: machining the stock both internally andexternally for a short distance rearwardly from the end of the stock toimpart prescribed external and internal diameters to the stock at itsend only; parting the machined portion of .the elongated stock to forman annular blank; coldextruding the machined annular blank into amultiplex structure having axially offset segments of annular shape anddifferent diameters; and separating thesegments 'of the multiplexstructure in a punching operation, whereby the separated segments becomebearing races;

4. The method claimed in claim 2 in which the steel stock is a seamlesssteel tube. V

5. The method claimed in claim 2 in which the steel stock is a hotrolled steel bar.

6. The method claimed in any of claim 2 in which the multiplex structureis a duplex structure the portions of which when separated constitutethe cup and the cone of a tapered roller bearing 7. A method accordingto claim 3 wherein the stock is turned in a lathe as it is machined.

8. A method according to claim 7 wherein the annular blank is partedfrom the remainder of the elongated stock by introducing a parting offtool into the rotating stock.

1. A method of manufacturing a cup and cone for a tapered roller bearingfrom elongated stock; said method comprising: sizing the end of theelongated stock both internally and externally to prescribed diametersby machining; parting the sized end portion of the elongated stock fromthe remainder of stock to form an annular blank; degreasing, barrelling,phosphating, and soaping the annular blank; thereafter extruding theannular blank into a duplex structure having two axially offset segmentsof different diameters; and separating the axially offset segments in apunching operation, whereby the segment of greater diameter becomes thecup and the segment of lesser diameter becomes the cone.
 2. A method ofmanufacturing bearing races from elongated steel stock, said methodcomprising: machining the stock both internally and externally to impartprescribed external and internal diameters to the end oF the stock andto remove metallurgical defects from the stock; parting at least aportion of the machined portion to form an annular blank, cold extrudingthe machined annular blank into a multiplex structure having axiallyoffset segments of annular shape and different diameters; and separatingthe segments of the multiplex structure in a punching operation, wherebythe separated segments become bearing races.
 3. A method ofmanufacturing bearing races from elongated steel stock, said methodcomprising: machining the stock both internally and externally for ashort distance rearwardly from the end of the stock to impart prescribedexternal and internal diameters to the stock at its end only; partingthe machined portion of the elongated stock to form an annular blank;cold extruding the machined annular blank into a multiplex structurehaving axially offset segments of annular shape and different diameters;and separating the segments of the multiplex structure in a punchingoperation, whereby the separated segments become bearing races.
 4. Themethod claimed in claim 2 in which the steel stock is a seamless steeltube.
 5. The method claimed in claim 2 in which the steel stock is a hotrolled steel bar.
 6. The method claimed in any of claim 2 in which themultiplex structure is a duplex structure the portions of which whenseparated constitute the cup and the cone of a tapered roller bearing.7. A method according to claim 3 wherein the stock is turned in a latheas it is machined.
 8. A method according to claim 7 wherein the annularblank is parted from the remainder of the elongated stock by introducinga parting off tool into the rotating stock.